Generation of supersonic and super-Alfvénic flowusing RF heating and a magnetic nozzle

摘要

Fast-flowing plasmas in supersonic and super-Alfvénic regime are generated in combinedrnexperiments of ICRH (ion cyclotron resonance heating) and acceleration in a magnetic nozzle.rnDuring RF (radio-frequency) wave excitation in a fast-flowing plasma produced by an MPDArn(Magnet-Plasma-Dynamic arcjet), strong ion cyclotron heating is clearly observed. In a divergingrnmagnetic nozzle, conversion of plasma thermal energy into plasma flow energy occurs under therncondition that magnetic moment μ is nearly constant. At the end of the magnetic nozzle regionrnAlfven Mach number as well as ion acoustic Mach number attains to more than unity, that isrnsupersonic and super-Alfvénic plasma flow is realized in a downstream region of a divergingrnmagnetic nozzle.